Table Of Contents
Source code for kivy.uix.scrollview
'''
Scroll View
===========
.. versionadded:: 1.0.4
The :class:`ScrollView` widget provides a scrollable/pannable viewport that is
clipped at the scrollview's bounding box.
Scrolling Behavior
------------------
The ScrollView accepts only one child and applies a viewport/window to it
according to the :attr:`scroll_x` and :attr:`scroll_y` properties. Touches are
analyzed to determine if the user wants to scroll or control the child in some
other manner - you cannot do both at the same time. To determine if interaction
is a scrolling gesture, these properties are used:
- :attr:`ScrollView.scroll_distance`: the minimum distance to travel,
defaults to 20 pixels.
- :attr:`ScrollView.scroll_timeout`: the maximum time period, defaults
to 250 milliseconds.
If a touch travels :attr:`~ScrollView.scroll_distance` pixels within the
:attr:`~ScrollView.scroll_timeout` period, it is recognized as a scrolling
gesture and translation (scroll/pan) will begin. If the timeout occurs, the
touch down event is dispatched to the child instead (no translation).
The default value for those settings can be changed in the configuration file::
[widgets]
scroll_timeout = 250
scroll_distance = 20
.. versionadded:: 1.1.1
ScrollView now animates scrolling in Y when a mousewheel is used.
Limiting to the X or Y Axis
---------------------------
By default, the ScrollView allows scrolling in both the X and Y axes. You can
explicitly disable scrolling on an axis by setting
:attr:`ScrollView.do_scroll_x` or :attr:`ScrollView.do_scroll_y` to False.
Managing the Content Size and Position
--------------------------------------
ScrollView manages the position of its children similarly to a
RelativeLayout (see :mod:`~kivy.uix.relativelayout`) but not the size. You must
carefully specify the `size_hint` of your content to get the desired
scroll/pan effect.
By default, size_hint is (1, 1), so the content size will fit your ScrollView
exactly (you will have nothing to scroll). You must deactivate at least one of
the size_hint instructions (x or y) of the child to enable scrolling.
To scroll a :class:`GridLayout` on Y-axis/vertically, set the child's width
identical to that of the ScrollView (size_hint_x=1, default), and set the
size_hint_y property to None::
layout = GridLayout(cols=1, spacing=10, size_hint_y=None)
# Make sure the height is such that there is something to scroll.
layout.bind(minimum_height=layout.setter('height'))
for i in range(30):
btn = Button(text=str(i), size_hint_y=None, height=40)
layout.add_widget(btn)
root = ScrollView(size_hint=(None, None), size=(400, 400))
root.add_widget(layout)
Effects
-------
.. versionadded:: 1.7.0
An effect is a subclass of :class:`~kivy.effects.scroll.ScrollEffect` that will
compute informations during the dragging, and apply transformation to the
:class:`ScrollView`. Depending of the effect, more computing can be done for
calculating over-scroll, bouncing, etc.
All the effects are located in the :mod:`kivy.effects`.
'''
__all__ = ('ScrollView', )
from functools import partial
from kivy.animation import Animation
from kivy.compat import string_types
from kivy.config import Config
from kivy.clock import Clock
from kivy.factory import Factory
from kivy.uix.stencilview import StencilView
from kivy.metrics import sp
from kivy.effects.dampedscroll import DampedScrollEffect
from kivy.properties import NumericProperty, BooleanProperty, AliasProperty, \
ObjectProperty, ListProperty, ReferenceListProperty, OptionProperty
# When we are generating documentation, Config doesn't exist
_scroll_timeout = _scroll_distance = 0
if Config:
_scroll_timeout = Config.getint('widgets', 'scroll_timeout')
_scroll_distance = sp(Config.getint('widgets', 'scroll_distance'))
[docs]class ScrollView(StencilView):
'''ScrollView class. See module documentation for more information.
.. versionchanged:: 1.7.0
`auto_scroll`, `scroll_friction`, `scroll_moves`, `scroll_stoptime' has
been deprecated, use :attr:`effect_cls` instead.
'''
scroll_distance = NumericProperty(_scroll_distance)
'''Distance to move before scrolling the :class:`ScrollView`, in pixels. As
soon as the distance has been traveled, the :class:`ScrollView` will start
to scroll, and no touch event will go to children.
It is advisable that you base this value on the dpi of your target device's
screen.
:attr:`scroll_distance` is a :class:`~kivy.properties.NumericProperty` and
defaults to 20 (pixels), according to the default value in user
configuration.
'''
scroll_wheel_distance = NumericProperty(20)
'''Distance to move when scrolling with a mouse wheel.
It is advisable that you base this value on the dpi of your target device's
screen.
.. versionadded:: 1.8.0
:attr:`scroll_wheel_distance` is a
:class:`~kivy.properties.NumericProperty` , defaults to 20 pixels.
'''
scroll_timeout = NumericProperty(_scroll_timeout)
'''Timeout allowed to trigger the :attr:`scroll_distance`, in milliseconds.
If the user has not moved :attr:`scroll_distance` within the timeout,
the scrolling will be disabled, and the touch event will go to the
children.
:attr:`scroll_timeout` is a :class:`~kivy.properties.NumericProperty` and
defaults to 55 (milliseconds) according to the default value in user
configuration.
.. versionchanged:: 1.5.0
Default value changed from 250 to 55.
'''
scroll_x = NumericProperty(0.)
'''X scrolling value, between 0 and 1. If 0, the content's left side will
touch the left side of the ScrollView. If 1, the content's right side will
touch the right side.
This property is controled by :class:`ScrollView` only if
:attr:`do_scroll_x` is True.
:attr:`scroll_x` is a :class:`~kivy.properties.NumericProperty` and
defaults to 0.
'''
scroll_y = NumericProperty(1.)
'''Y scrolling value, between 0 and 1. If 0, the content's bottom side will
touch the bottom side of the ScrollView. If 1, the content's top side will
touch the top side.
This property is controled by :class:`ScrollView` only if
:attr:`do_scroll_y` is True.
:attr:`scroll_y` is a :class:`~kivy.properties.NumericProperty` and
defaults to 1.
'''
do_scroll_x = BooleanProperty(True)
'''Allow scroll on X axis.
:attr:`do_scroll_x` is a :class:`~kivy.properties.BooleanProperty` and
defaults to True.
'''
do_scroll_y = BooleanProperty(True)
'''Allow scroll on Y axis.
:attr:`do_scroll_y` is a :class:`~kivy.properties.BooleanProperty` and
defaults to True.
'''
def _get_do_scroll(self):
return (self.do_scroll_x, self.do_scroll_y)
def _set_do_scroll(self, value):
if type(value) in (list, tuple):
self.do_scroll_x, self.do_scroll_y = value
else:
self.do_scroll_x = self.do_scroll_y = bool(value)
do_scroll = AliasProperty(_get_do_scroll, _set_do_scroll,
bind=('do_scroll_x', 'do_scroll_y'))
'''Allow scroll on X or Y axis.
:attr:`do_scroll` is a :class:`~kivy.properties.AliasProperty` of
(:attr:`do_scroll_x` + :attr:`do_scroll_y`)
'''
def _get_vbar(self):
# must return (y, height) in %
# calculate the viewport size / scrollview size %
if self._viewport is None:
return 0, 1.
vh = self._viewport.height
h = self.height
if vh < h or vh == 0:
return 0, 1.
ph = max(0.01, h / float(vh))
sy = min(1.0, max(0.0, self.scroll_y))
py = (1. - ph) * sy
return (py, ph)
vbar = AliasProperty(_get_vbar, None, bind=(
'scroll_y', '_viewport', 'viewport_size'))
'''Return a tuple of (position, size) of the vertical scrolling bar.
.. versionadded:: 1.2.0
The position and size are normalized between 0-1, and represent a
percentage of the current scrollview height. This property is used
internally for drawing the little vertical bar when you're scrolling.
:attr:`vbar` is a :class:`~kivy.properties.AliasProperty`, readonly.
'''
def _get_hbar(self):
# must return (x, width) in %
# calculate the viewport size / scrollview size %
if self._viewport is None:
return 0, 1.
vw = self._viewport.width
w = self.width
if vw < w or vw == 0:
return 0, 1.
pw = max(0.01, w / float(vw))
sx = min(1.0, max(0.0, self.scroll_x))
px = (1. - pw) * sx
return (px, pw)
hbar = AliasProperty(_get_hbar, None, bind=(
'scroll_x', '_viewport', 'viewport_size'))
'''Return a tuple of (position, size) of the horizontal scrolling bar.
.. versionadded:: 1.2.0
The position and size are normalized between 0-1, and represent a
percentage of the current scrollview height. This property is used
internally for drawing the little horizontal bar when you're scrolling.
:attr:`vbar` is a :class:`~kivy.properties.AliasProperty`, readonly.
'''
bar_color = ListProperty([.7, .7, .7, .9])
'''Color of horizontal / vertical scroll bar, in RGBA format.
.. versionadded:: 1.2.0
:attr:`bar_color` is a :class:`~kivy.properties.ListProperty` and defaults
to [.7, .7, .7, .9].
'''
bar_width = NumericProperty('2dp')
'''Width of the horizontal / vertical scroll bar. The width is interpreted
as a height for the horizontal bar.
.. versionadded:: 1.2.0
:attr:`bar_width` is a :class:`~kivy.properties.NumericProperty` and
defaults to 2.
'''
bar_pos_x = OptionProperty('bottom', options=('top', 'bottom'))
'''Which side of the ScrollView the horizontal scroll bar should go
on. Possible values are 'top' and 'bottom'.
.. versionadded:: 1.8.0
:attr:`bar_pos_x` is an :class:`~kivy.properties.OptionProperty`,
default to 'bottom'
'''
bar_pos_y = OptionProperty('right', options=('left', 'right'))
'''Which side of the ScrollView the vertical scroll bar should go
on. Possible values are 'left' and 'right'.
.. versionadded:: 1.8.0
:attr:`bar_pos_y` is an :class:`~kivy.properties.OptionProperty`,
default to 'right'
'''
bar_pos = ReferenceListProperty(bar_pos_x, bar_pos_y)
'''Which side of the scroll view to place each of the bars on.
:attr:`bar_pos` is a :class:`~kivy.properties.ReferenceListProperty` of
(:attr:`bar_pos_x`, :attr:`bar_pos_y`)
'''
bar_margin = NumericProperty(0)
'''Margin between the bottom / right side of the scrollview when drawing
the horizontal / vertical scroll bar.
.. versionadded:: 1.2.0
:attr:`bar_margin` is a :class:`~kivy.properties.NumericProperty`, default
to 0
'''
effect_cls = ObjectProperty(DampedScrollEffect, allownone=True)
'''Class effect to instanciate for X and Y axis.
.. versionadded:: 1.7.0
:attr:`effect_cls` is an :class:`~kivy.properties.ObjectProperty` and
defaults to :class:`DampedScrollEffect`.
.. versionchanged:: 1.8.0
If you set a string, the :class:`~kivy.factory.Factory` will be used to
resolve the class.
'''
effect_x = ObjectProperty(None, allownone=True)
'''Effect to apply for the X axis. If None is set, an instance of
:attr:`effect_cls` will be created.
.. versionadded:: 1.7.0
:attr:`effect_x` is an :class:`~kivy.properties.ObjectProperty` and
defaults to None.
'''
effect_y = ObjectProperty(None, allownone=True)
'''Effect to apply for the Y axis. If None is set, an instance of
:attr:`effect_cls` will be created.
.. versionadded:: 1.7.0
:attr:`effect_y` is an :class:`~kivy.properties.ObjectProperty` and
defaults to None, read-only.
'''
viewport_size = ListProperty([0, 0])
'''(internal) Size of the internal viewport. This is the size of your only
child in the scrollview.
'''
scroll_type = OptionProperty(['content'], options=(['content'], ['bars'],
['bars', 'content'], ['content', 'bars']))
'''Sets the type of scrolling to use for the content of the scrollview.
Available options are: ['content'], ['bars'], ['bars', 'content'].
.. versionadded:: 1.8.0
:attr:`scroll_type` is a :class:`~kivy.properties.OptionProperty`, defaults
to ['content'].
'''
# private, for internal use only
_viewport = ObjectProperty(None, allownone=True)
bar_alpha = NumericProperty(1.)
def _set_viewport_size(self, instance, value):
self.viewport_size = value
def on__viewport(self, instance, value):
if value:
value.bind(size=self._set_viewport_size)
self.viewport_size = value.size
def __init__(self, **kwargs):
self._touch = None
self._trigger_update_from_scroll = Clock.create_trigger(
self.update_from_scroll, -1)
# create a specific canvas for the viewport
from kivy.graphics import PushMatrix, Translate, PopMatrix, Canvas
self.canvas_viewport = Canvas()
self.canvas = Canvas()
with self.canvas_viewport.before:
PushMatrix()
self.g_translate = Translate(0, 0)
with self.canvas_viewport.after:
PopMatrix()
super(ScrollView, self).__init__(**kwargs)
# now add the viewport canvas to our canvas
self.canvas.add(self.canvas_viewport)
effect_cls = self.effect_cls
if isinstance(effect_cls, string_types):
effect_cls = Factory.get(effect_cls)
if self.effect_x is None and effect_cls is not None:
self.effect_x = effect_cls(target_widget=self._viewport)
if self.effect_y is None and effect_cls is not None:
self.effect_y = effect_cls(target_widget=self._viewport)
self.bind(
width=self._update_effect_x_bounds,
height=self._update_effect_y_bounds,
viewport_size=self._update_effect_bounds,
_viewport=self._update_effect_widget,
scroll_x=self._trigger_update_from_scroll,
scroll_y=self._trigger_update_from_scroll,
pos=self._trigger_update_from_scroll,
size=self._trigger_update_from_scroll)
self._update_effect_widget()
self._update_effect_x_bounds()
self._update_effect_y_bounds()
def on_effect_x(self, instance, value):
if value:
value.bind(scroll=self._update_effect_x)
value.target_widget = self._viewport
def on_effect_y(self, instance, value):
if value:
value.bind(scroll=self._update_effect_y)
value.target_widget = self._viewport
def on_effect_cls(self, instance, cls):
if isinstance(cls, string_types):
cls = Factory.get(cls)
self.effect_x = cls(target_widget=self._viewport)
self.effect_x.bind(scroll=self._update_effect_x)
self.effect_y = cls(target_widget=self._viewport)
self.effect_y.bind(scroll=self._update_effect_y)
def _update_effect_widget(self, *args):
if self.effect_x:
self.effect_x.target_widget = self._viewport
if self.effect_y:
self.effect_y.target_widget = self._viewport
def _update_effect_x_bounds(self, *args):
if not self._viewport or not self.effect_x:
return
self.effect_x.min = -(self.viewport_size[0] - self.width)
self.effect_x.max = 0
self.effect_x.value = self.effect_x.min * self.scroll_x
def _update_effect_y_bounds(self, *args):
if not self._viewport or not self.effect_y:
return
self.effect_y.min = -(self.viewport_size[1] - self.height)
self.effect_y.max = 0
self.effect_y.value = self.effect_y.min * self.scroll_y
def _update_effect_bounds(self, *args):
if not self._viewport:
return
if self.effect_x:
self._update_effect_x_bounds()
if self.effect_y:
self._update_effect_y_bounds()
def _update_effect_x(self, *args):
vp = self._viewport
if not vp or not self.effect_x:
return
sw = vp.width - self.width
if sw < 1:
return
sx = self.effect_x.scroll / float(sw)
self.scroll_x = -sx
self._trigger_update_from_scroll()
def _update_effect_y(self, *args):
vp = self._viewport
if not vp or not self.effect_y:
return
sh = vp.height - self.height
if sh < 1:
return
sy = self.effect_y.scroll / float(sh)
self.scroll_y = -sy
self._trigger_update_from_scroll()
def to_local(self, x, y, **k):
tx, ty = self.g_translate.xy
return x - tx, y - ty
def to_parent(self, x, y, **k):
tx, ty = self.g_translate.xy
return x + tx, y + ty
def simulate_touch_down(self, touch):
# at this point the touch is in parent coords
touch.push()
touch.apply_transform_2d(self.to_local)
ret = super(ScrollView, self).on_touch_down(touch)
touch.pop()
return ret
def on_touch_down(self, touch):
if not self.collide_point(*touch.pos):
touch.ud[self._get_uid('svavoid')] = True
return
if self.disabled:
return True
if self._touch or (not (self.do_scroll_x or self.do_scroll_y)):
return self.simulate_touch_down(touch)
# handle mouse scrolling, only if the viewport size is bigger than the
# scrollview size, and if the user allowed to do it
vp = self._viewport
scroll_type = self.scroll_type
ud = touch.ud
scroll_bar = 'bars' in scroll_type
# check if touch is in bar_x(horizontal) or bay_y(bertical)
ud['in_bar_x'] = ud['in_bar_y'] = False
width_scrollable = vp.width > self.width
height_scrollable = vp.height > self.height
bar_pos_x = self.bar_pos_x[0]
bar_pos_y = self.bar_pos_y[0]
d = {'b': True if touch.y < self.y + self.bar_width else False,
't': True if touch.y > self.top - self.bar_width else False,
'l': True if touch.x < self.x + self.bar_width else False,
'r': True if touch.x > self.right - self.bar_width else False}
if scroll_bar:
if (width_scrollable and d[bar_pos_x]):
ud['in_bar_x'] = True
if (height_scrollable and d[bar_pos_y]):
ud['in_bar_y'] = True
if vp and 'button' in touch.profile and \
touch.button.startswith('scroll'):
btn = touch.button
m = sp(self.scroll_wheel_distance)
e = None
if (self.effect_x and self.do_scroll_y and height_scrollable
and btn in ('scrolldown', 'scrollup')):
e = self.effect_x if ud['in_bar_x'] else self.effect_y
elif (self.effect_y and self.do_scroll_x and width_scrollable
and btn in ('scrollleft', 'scrollright')):
e = self.effect_y if ud['in_bar_y'] else self.effect_x
if e:
if btn in ('scrolldown', 'scrollleft'):
e.value = max(e.value - m, e.min)
e.velocity = 0
elif btn in ('scrollup', 'scrollright'):
e.value = min(e.value + m, e.max)
e.velocity = 0
touch.ud[self._get_uid('svavoid')] = True
e.trigger_velocity_update()
return True
# no mouse scrolling, so the user is going to drag the scrollview with
# this touch.
self._touch = touch
uid = self._get_uid()
touch.grab(self)
ud[uid] = {
'mode': 'unknown',
'dx': 0,
'dy': 0,
'user_stopped': False,
'frames': Clock.frames,
'time': touch.time_start}
if self.do_scroll_x and self.effect_x and not ud['in_bar_x']:
self.effect_x.start(touch.x)
if self.do_scroll_y and self.effect_y and not ud['in_bar_y']:
self.effect_y.start(touch.y)
if (ud.get('in_bar_x', False) or ud.get('in_bar_y', False)):
return
if scroll_type == ['bars']:
# touch is in parent, but _change_touch_mode expects window coords
touch.push()
touch.apply_transform_2d(self.to_local)
touch.apply_transform_2d(self.to_window)
self._change_touch_mode()
touch.pop()
return False
else:
Clock.schedule_once(self._change_touch_mode,
self.scroll_timeout / 1000.)
return True
def on_touch_move(self, touch):
if self._get_uid('svavoid') in touch.ud:
return
if self._touch is not touch:
# touch is in parent
touch.push()
touch.apply_transform_2d(self.to_local)
super(ScrollView, self).on_touch_move(touch)
touch.pop()
return self._get_uid() in touch.ud
if touch.grab_current is not self:
return True
uid = self._get_uid()
ud = touch.ud[uid]
mode = ud['mode']
# check if the minimum distance has been travelled
if mode == 'unknown' or mode == 'scroll':
if self.do_scroll_x and self.effect_x:
width = self.width
if touch.ud.get('in_bar_x', False):
dx = touch.dx / float(width - width * self.hbar[1])
self.scroll_x = min(max(self.scroll_x + dx, 0.), 1.)
self._trigger_update_from_scroll()
else:
if self.scroll_type != ['bars']:
self.effect_x.update(touch.x)
if self.do_scroll_y and self.effect_y:
height = self.height
if touch.ud.get('in_bar_y', False):
dy = touch.dy / float(height - height * self.vbar[1])
self.scroll_y = min(max(self.scroll_y + dy, 0.), 1.)
self._trigger_update_from_scroll()
else:
if self.scroll_type != ['bars']:
self.effect_y.update(touch.y)
if mode == 'unknown':
ud['dx'] += abs(touch.dx)
ud['dy'] += abs(touch.dy)
if ud['dx'] > self.scroll_distance:
if not self.do_scroll_x:
# touch is in parent, but _change expects window coords
touch.push()
touch.apply_transform_2d(self.to_local)
touch.apply_transform_2d(self.to_window)
self._change_touch_mode()
touch.pop()
return
mode = 'scroll'
if ud['dy'] > self.scroll_distance:
if not self.do_scroll_y:
# touch is in parent, but _change expects window coords
touch.push()
touch.apply_transform_2d(self.to_local)
touch.apply_transform_2d(self.to_window)
self._change_touch_mode()
touch.pop()
return
mode = 'scroll'
ud['mode'] = mode
if mode == 'scroll':
ud['dt'] = touch.time_update - ud['time']
ud['time'] = touch.time_update
ud['user_stopped'] = True
return True
def on_touch_up(self, touch):
if self._get_uid('svavoid') in touch.ud:
return
if self in [x() for x in touch.grab_list]:
touch.ungrab(self)
self._touch = None
uid = self._get_uid()
ud = touch.ud[uid]
if self.do_scroll_x and self.effect_x:
if not touch.ud.get('in_bar_x', False) and\
self.scroll_type != ['bars']:
self.effect_x.stop(touch.x)
if self.do_scroll_y and self.effect_y and\
self.scroll_type != ['bars']:
if not touch.ud.get('in_bar_y', False):
self.effect_y.stop(touch.y)
if ud['mode'] == 'unknown':
# we must do the click at least..
# only send the click if it was not a click to stop
# autoscrolling
if not ud['user_stopped']:
self.simulate_touch_down(touch)
Clock.schedule_once(partial(self._do_touch_up, touch), .2)
Clock.unschedule(self._update_effect_bounds)
Clock.schedule_once(self._update_effect_bounds)
else:
if self._touch is not touch and self.uid not in touch.ud:
# touch is in parents
touch.push()
touch.apply_transform_2d(self.to_local)
super(ScrollView, self).on_touch_up(touch)
touch.pop()
# if we do mouse scrolling, always accept it
if 'button' in touch.profile and touch.button.startswith('scroll'):
return True
return self._get_uid() in touch.ud
[docs] def update_from_scroll(self, *largs):
'''Force the reposition of the content, according to current value of
:attr:`scroll_x` and :attr:`scroll_y`.
This method is automatically called when one of the :attr:`scroll_x`,
:attr:`scroll_y`, :attr:`pos` or :attr:`size` properties change, or
if the size of the content changes.
'''
if not self._viewport:
return
vp = self._viewport
# update from size_hint
if vp.size_hint_x is not None:
vp.width = vp.size_hint_x * self.width
if vp.size_hint_y is not None:
vp.height = vp.size_hint_y * self.height
if vp.width > self.width:
sw = vp.width - self.width
x = self.x - self.scroll_x * sw
else:
x = self.x
if vp.height > self.height:
sh = vp.height - self.height
y = self.y - self.scroll_y * sh
else:
y = self.top - vp.height
# from 1.8.0, we now use a matrix by default, instead of moving the
# widget position behind. We set it here, but it will be a no-op most of
# the time.
vp.pos = 0, 0
self.g_translate.xy = x, y
# new in 1.2.0, show bar when scrolling happen
# and slowly remove them when no scroll is happening.
self.bar_alpha = 1.
Animation.stop_all(self, 'bar_alpha')
Clock.unschedule(self._start_decrease_alpha)
Clock.schedule_once(self._start_decrease_alpha, .5)
def _start_decrease_alpha(self, *l):
self.bar_alpha = 1.
# show bars if scroll_type != content
bar_alpha = .2 if self.scroll_type != ['content'] else 0
Animation(bar_alpha=bar_alpha, d=.5, t='out_quart').start(self)
#
# Private
#
def add_widget(self, widget, index=0):
if self._viewport:
raise Exception('ScrollView accept only one widget')
canvas = self.canvas
self.canvas = self.canvas_viewport
super(ScrollView, self).add_widget(widget, index)
self.canvas = canvas
self._viewport = widget
widget.bind(size=self._trigger_update_from_scroll)
self._trigger_update_from_scroll()
def remove_widget(self, widget):
canvas = self.canvas
self.canvas = self.canvas_viewport
super(ScrollView, self).remove_widget(widget)
self.canvas = canvas
if widget is self._viewport:
self._viewport = None
def _get_uid(self, prefix='sv'):
return '{0}.{1}'.format(prefix, self.uid)
def _change_touch_mode(self, *largs):
if not self._touch:
return
uid = self._get_uid()
touch = self._touch
ud = touch.ud[uid]
if ud['mode'] != 'unknown' or ud['user_stopped']:
return
diff_frames = Clock.frames - ud['frames']
# in order to be able to scroll on very slow devices, let at least 3
# frames displayed to accumulate some velocity. And then, change the
# touch mode. Otherwise, we might never be able to compute velocity, and
# no way to scroll it. See #1464 and #1499
if diff_frames < 3:
Clock.schedule_once(self._change_touch_mode, 0)
return
if self.do_scroll_x and self.effect_x:
self.effect_x.cancel()
if self.do_scroll_y and self.effect_y:
self.effect_y.cancel()
# XXX the next line was in the condition. But this stop
# the possibily to "drag" an object out of the scrollview in the
# non-used direction: if you have an horizontal scrollview, a
# vertical gesture will not "stop" the scroll view to look for an
# horizontal gesture, until the timeout is done.
# and touch.dx + touch.dy == 0:
touch.ungrab(self)
self._touch = None
# touch is in window coords
touch.push()
touch.apply_transform_2d(self.to_widget)
touch.apply_transform_2d(self.to_parent)
self.simulate_touch_down(touch)
touch.pop()
return
def _do_touch_up(self, touch, *largs):
# touch is in window coords
touch.push()
touch.apply_transform_2d(self.to_widget)
super(ScrollView, self).on_touch_up(touch)
touch.pop()
# don't forget about grab event!
for x in touch.grab_list[:]:
touch.grab_list.remove(x)
x = x()
if not x:
continue
touch.grab_current = x
# touch is in window coords
touch.push()
touch.apply_transform_2d(self.to_widget)
super(ScrollView, self).on_touch_up(touch)
touch.pop()
touch.grab_current = None
if __name__ == '__main__':
from kivy.app import App
from kivy.uix.gridlayout import GridLayout
from kivy.uix.button import Button
class ScrollViewApp(App):
def build(self):
layout1 = GridLayout(cols=4, spacing=10, size_hint=(None, None))
layout1.bind(minimum_height=layout1.setter('height'),
minimum_width=layout1.setter('width'))
for i in range(40):
btn = Button(text=str(i), size_hint=(None, None),
size=(200, 100))
layout1.add_widget(btn)
scrollview1 = ScrollView(bar_width='2dp')
scrollview1.add_widget(layout1)
layout2 = GridLayout(cols=4, spacing=10, size_hint=(None, None))
layout2.bind(minimum_height=layout2.setter('height'),
minimum_width=layout2.setter('width'))
for i in range(40):
btn = Button(text=str(i), size_hint=(None, None),
size=(200, 100))
layout2.add_widget(btn)
scrollview2 = ScrollView(scroll_type=['bars'],
bar_width='9dp',
scroll_wheel_distance=100)
scrollview2.add_widget(layout2)
root = GridLayout(cols=2)
root.add_widget(scrollview1)
root.add_widget(scrollview2)
return root
ScrollViewApp().run()